Volume 2 addresses the methods in use or in development for enhancing the visual perception of digital medical images obtained by a wide variety of imaging modalities and for image analysis as an aid to detection and diagnosis.

Preface

During the last few decades of the twentieth century, partly in
concert with the increasing availability of relatively inexpensive
computational resources, medical imaging technology, which had for nearly
80 years been almost exclusively concerned with conventional film/screen
x-ray imaging, experienced the development and commercialization of a
plethora of new imaging technologies. Computed tomography, MRI imaging,
digital subtraction angiography, Doppler ultrasound imaging, various
imaging techniques based on nuclear emission (PET, SPECT, etc.) have all
been valuable additions to the radiologist's arsenal of imaging tools
toward ever more reliable detection and diagnosis of disease. More
recently, conventional x-ray imaging technology itself is being challenged
by the emerging possibilities offered by flat panel x-ray detectors. In
addition to the concurrent development of rapid and relatively inexpensive
computational resources, this era of rapid change owes much of its success
to an improved understanding of the information theoretic principles on
which the development and maturation of these new technologies is based. A
further important corollary of these developments in medical imaging
technology has been the relatively rapid development and deployment of
methods for archiving and transmitting digital images. Much of this
engineering development continues to make use of the ongoing revolution in
rapid communications technology offered by increasing bandwidth. A little
more than 100 years after the discovery of x-rays, this three-volume
Handbook of Medical Imaging is intended to provide a comprehensive overview
of the theory and current practice of Medical Imaging as we enter the 21st
century. Volume I, which concerns the physics and the psychophysics of
medical imaging, begins with a fundamental description of x-ray imaging
physics and progresses to a review of linear systems theory and its
application to an understanding of signal and noise propagation in such
systems. The subsequent chapters concern the physics of the important
individual imaging modalities currently in use: ultrasound, CT, MRI, the
recently emerging technology of flat panel x-ray detectors and, in
particular, their application to mammography. The second half of this
volume, on psychophysics, describes the current understanding of the
relationship between image quality metrics and visual perception of the
diagnostic information carried by medical images. In addition, various
models of perception in the presence of noise or "unwanted" signal are
described. Lastly, the statistical methods used in determining the efficacy
of medical imaging tasks, ROC analysis and its variants, are discussed.
Volume II, which concerns Medical Image Processing and Image Analysis,
provides descriptions of the methods currently being used or being
developed for enhancing the visual perception of digital medical images
obtained by a wide variety of imaging modalities and for image analysis as
a possible aid to detection and diagnosis. Image analysis may be of
particular significance in future developments, since, aside from the
inherent efficiencies of digital imaging, the possibility of performing
analytic computation on digital information offers exciting prospects for
improved detection and diagnostic accuracy. Lastly, Volume III, describes
the concurrent engineering developments which or in some instances have
actually enabled further developments in digital diagnostic imaging. Among
the latter, the ongoing development of bright, high resolution monitors for
viewing high resolution digital radiographs, particularly for mammography,
stands out. Other efforts, in this field offer exciting, previously
inconceivable possibilities, e.g., the use of 3D (virtual reality)
visualization for surgical planning and for image guided surgery. Another
important area of ongoing research in this field involves image
compression, which in concert with increasing bandwidth, enables rapid
image communication and increases storage efficiency. The latter will be
particularly important with the expected increase in the acceptance of
digital radiography as a replacement for conventional film/screen imaging,
which is expected to generate data volumes far in excess of currently
available capacity. The second half of this volume describes current
developments in Picture Archiving and Communications (PACS) technology,
with particular emphasis on integration of the new and emerging imaging
technologies into the hospital environment and the provision of means for
rapid retrieval and transmission of imaging data. Developments in rapid
transmission are of particular importance since they will enable access via
telemedicine to remote or underdeveloped areas. As evidenced by the variety
of the research described in these volumes, medical imaging is still
undergoing very rapid change. The editors hope that this publication will
provide at least some of the information by means of which students,
researchers and practitioners in this exciting field are aided in
contributing to it ever increasing usefulness.